1. Field of the Invention
The present invention relates to a photographing lens system suitable for use in a compact lens-shutter type camera and, more particularly, to a photographing lens system having a wide view angle.
2. RELATED BACKGROUND ART
Behind shutter tessar type lens and tripplet type lens are known as photographing lens for compact lens-shutter type camera. These photographing lenses are advantageous in that they have superior performance despite very simple constructions and in that they enable focusing mechanism to be simplified in construction because the stop is located close to the image. Another advantage is that the focal distance of the whole lens system can easily be increased by attaching a rear converter to the image side of these lens systems.
In recent years, there is a diversified demand for lens-shutter type cameras. For instance, there is in one hand an increasing demand for photographing lens system having wider angles, while on the other hand multi-focus lens systems and large-diameter lenses are required. The tessar-type lens and tripplet-type lens, however, have view anglers which are about 65.degree. at the greatest and cannot be regarded as being wide angle lenses.
Hitherto, so-called Biogon type lens and retro-focus-type lens have been known as wide angle lenses. These lenses, however, are quite complicated in construction and cannot suitably be used as photographing lens system for lens-shutter-type camera, considering cost and lens size.
In these known wide angle lenses, stop is incorporated in the optical system so that the focusing mechanism of the camera is impractically complicated. Furthermore, it is not easy to mount a rear converter on these known wide angle lenses, making it difficult to design and construct a two-focus camera.